Aims. This study uses prospective registry data to compare early patient outcomes following arthroscopic repair or debridement of the acetabular labrum. Methods. Data on adult patients who underwent arthroscopic labral debridement or repair between 1 January 2012 and 31 July 2019 were extracted from the UK Non-Arthroplasty Hip Registry. Patients who underwent microfracture, osteophyte excision, or a concurrent extra-articular procedure were excluded. The EuroQol five-dimension (EQ-5D) and International Hip Outcome Tool 12 (iHOT-12) questionnaires were collected preoperatively and at six and 12 months post-operatively. Due to concerns over differential questionnaire non-response between the two groups, a combination of random sampling, propensity score matching, and pooled multivariable linear regression models were employed to compare iHOT-12 improvement. Results. A total of 2,025 labral debridements (55%) and 1,659 labral repairs (45%) were identified. Both groups saw significant (p < 0.001) EQ-5D and iHOT-12 gain compared to preoperative scores at 12 months (iHOT-12 improvement: labral repair = +28.7 (95% confidence interval (CI) 26.4 to 30.9), labral debridement = +24.7 (95% CI 22.5 to 27.0)), however there was no significant difference between procedures after multivariable modelling. Overall, 66% of cases achieved the minimum clinically important difference (MCID) and 48% achieved substantial clinical benefit at 12 months. Conclusion. Both labral procedures were successful in significantly improving early functional outcome following hip arthroscopy, regardless of age or sex. Labral repair was associated with superior outcomes in univariable analysis, however there was no significant superiority demonstrated in the multivariable model. Level of evidence: III. Cite this article: Bone Jt Open 2022;3(4):291–301

Aims. Treatment outcomes for methicillin-resistant Staphylococcus aureus (MRSA) periprosthetic joint infection (PJI) using systemic vancomycin and antibacterial cement spacers during two-stage revision arthroplasty remain unsatisfactory. This study explored the efficacy and safety of intra-articular vancomycin injections for PJI control after debridement and cement spacer implantation in a rat model. Methods. Total knee arthroplasty (TKA), MRSA inoculation, debridement, and vancomycin-spacer implantation were performed successively in rats to mimic first-stage PJI during the two-stage revision arthroplasty procedure. Vancomycin was administered intraperitoneally or intra-articularly for two weeks to control the infection after debridement and spacer implantation. Results. Rats receiving intra-articular vancomycin showed the best outcomes among the four treatment groups, with negative bacterial cultures, increased weight gain, increased capacity for weightbearing activities, increased residual bone volume preservation, and reduced inflammatory reactions in the joint tissues, indicating MRSA eradication in the knee. The vancomycin-spacer and/or systemic vancomycin failed to eliminate the MRSA infections following a two-week antibiotic course. Serum vancomycin levels did not reach nephrotoxic levels in any group. Mild renal histopathological changes, without changes in serum creatinine levels, were observed in the intraperitoneal vancomycin group compared with the intra-articular vancomycin group, but no changes in hepatic structure or serum alanine aminotransferase or aspartate aminotransferase levels were observed. No local complications were observed, such as sinus tract or non-healing surgical incisions. Conclusion. Intra-articular vancomycin injection was effective and safe for PJI control following debridement and spacer implantation in a rat model during two-stage revision arthroplasties, with better outcomes than systemic vancomycin administration. Cite this article: Bone Joint Res 2022;11(6):371–385

Aims. The aims of the study were to review and analyse the reported series of debridement, antibiotics and implant retention (DAIR) in the management of infected total hip arthroplasties (THAs) to establish the overall success and the influencing factors. Patients and methods. Using a standardised recognised study protocol, meta-analysis of observational studies in epidemiology guidelines, a comprehensive review and analysis of the literature was performed. The primary outcome measure was the success of treatment. The search strategy and inclusion criteria which involved an assessment of quality yielded 39 articles for analysis, which included 1296 patients. Results. The proportion of success following DAIR in the management of an infected THA appeared to improve after 2004 with a pooled mean proportion of success of 72.2%. For all reported series, from 1977 onwards, there was improved success with early debridement (< 7 days; 75.7%) and exchange of modular components (77.5%). There was a statistically non-significant improvement if debridement was performed within four weeks of the initial procedure (73.0%). Conclusion. The reported success following DAIR has improved since 2004. The only determinants of outcome which we found were the timing of debridement after the onset of symptoms of infection and the exchange of modular components. Cite this article: Bone Joint J 2017;99-B:1488–66

We have reviewed the current literature to compare the results of surgery aimed to repair or debride a damaged acetabular labrum. We identified 28 studies to be included in the review containing a total of 1631 hips in 1609 patients. Of these studies 12 reported a mean rate of good results of 82% (from 67% to 100%) for labral debridement. Of the 16 studies that reported a combination of debridement and re-attachment, five reported a comparative outcome for the two methods, four reported better results with re-attachment and one study did not find any significant difference in outcomes. Due to the heterogeneity of the studies it was not possible to perform a meta-analysis or draw accurate conclusions. Confounding factors in the studies include selection bias, use of historical controls and high rates of loss of follow-up. It seems logical to repair an unstable tear in a good quality labrum with good potential to heal in order potentially to preserve its physiological function. A degenerative labrum on the other hand may be the source of discomfort and its preservation may result in persistent pain and the added risk of failure of re-attachment. The results of the present study do not support routine refixation for all labral tears. Cite this article: Bone Joint J 2014;96-B:24–30

Aims. To analyse the effectiveness of debridement and implant retention (DAIR) in patients with hip periprosthetic joint infection (PJI) and the relationship to patient characteristics. The outcome was evaluated in hips with confirmed PJI and a follow-up of not less than two years. Patients and Methods. Patients in whom DAIR was performed were identified from our hip arthroplasty register (between 2004 and 2013). Adherence to criteria for DAIR was assessed according to a previously published algorithm. Results. DAIR was performed as part of a curative procedure in 46 hips in 42 patients. The mean age was 73.2 years (44.6 to 87.7), including 20 women and 22 men. In 34 hips in 32 patients (73.9%), PJI was confirmed. In 12 hips, the criteria for PJI were not fulfilled and antibiotics stopped. In 41 (89.1%) of all hips and in 32 (94.1%) of the confirmed PJIs, all criteria for DAIR were fulfilled. In patients with exogenous PJI, DAIR was performed not more than three days after referral. In haematogenous infections, the duration of symptoms did not exceed 21 days. In 28 hips, a single debridement and in six hips two surgical debridements were required. In 28 (87.5%) of 32 patients, the total treatment duration was three months. Failure was noted in three hips (9%). Long-term follow-up results (mean 4.0 years, 1.4 to 10) were available in 30 of 34 (88.2%) confirmed PJIs. The overall successful outcome rate was 91% in 34 hips, and 90% in 30 hips with long-term follow-up results. . Conclusion. Prompt surgical treatment with DAIR, following strict diagnostic and therapeutic criteria, in patients with suspected periprosthetic joint infection, can lead to high rates of success in eradicating the infection. Cite this article: Bone Joint J 2017;99-B:330–6

Most animal studies indicate that early irrigation and debridement reduce infection after an open fracture. Unfortunately, these studies often do not involve antibiotics. Clinical studies indicate that the timing of initial debridement does not affect the rate of infection but these studies are observational and fraught with confounding variables. The purpose of this study was to control these variables using an animal model incorporating systemic antibiotics and surgical treatment. We used a rat femur model with a defect which was contaminated with Staphylococcus aureus and treated with a three-day course of systemic cefazolin (5 mg/kg 12-hourly) and debridement and irrigation, both of which were initiated independently at two, six and 24 hour time points. After 14 days the bone and hardware were harvested for separate microbiological analysis. No animal that received antibiotics and surgery two hours after injury had detectable bacteria. When antibiotics were started at two hours, a delay in surgical treatment from two to six hours significantly increased the development of infection (p = 0.047). However, delaying surgery to 24 hours increase the rate of infection, but not significantly (p = 0.054). The timing of antibiotics had a more significant effect on the proportion of positive samples than earlier surgery. Delaying antibiotics to six or 24 hours had a profoundly detrimental effect on the infection rate regardless of the timing of surgery. These findings are consistent with the concept that bacteria progress from a vulnerable planktonic form to a treatment-resistant biofilm

Open debridement and Outerbridge and Kashiwagi debridement arthroplasty (OK procedure) are common surgical treatments for elbow arthritis. However, the literature contains little information on the long-term survivorship of these procedures. The purpose of this study was to determine the survivorship after elbow debridement techniques until conversion to total elbow arthroplasty and revision surgery. We performed a retrospective chart review of patients who underwent open elbow surgical debridement (open debridement, OK procedure) between 2000 and 2015. Patients were diagnosed with primary elbow osteoarthritis, post-traumatic arthritis, or inflammatory arthritis. A total of 320 patients had primary surgery including open debridement (n=142) and OK procedure (n=178), and of these 33 patients required a secondary revision surgery (open debridement, n=14 and OK procedure, n=19). The average follow-up time was 11.5 years (5.5 - 21.5 years). Survivorship was analyzed with Kaplan-Meier curves and Log Rank test. A Cox proportional hazards model was used assess the likelihood of conversion to total elbow arthroplasty or revision surgery while adjusting for covariates (age, gender, diagnosis). Significance was set p<0.05. Kaplan-Meier survival curves showed open debridement was 100.00% at 1 year, 99.25% at 5 years, and 98.49% at 10 years and for OK procedure 100.00% at 1 year, 98.80% at 5 years, 97.97% at 10 years (p=0.87) for conversion to total elbow arthroplasty. There was no difference in survivorship between procedures after adjusting for significant covariates with the cox proportional hazard model. The rate of revision for open debridement and OK procedure was similar at 11.31% rand 11.48% after 10 years respectively. There were higher rates of revision surgery in patients with open debridement (hazard ratio, 4.84 CI 1.29 – 18.17, p = 0.019) compared to OK procedure after adjusting for covariates. We also performed a stratified analysis with radiographic severity as an effect modifier and showed grade 3 arthritis did better with the OK procedure compared to open debridement for survivorship until revision surgery (p=0.05). However, this difference was not found for grade 1 or grade 2 arthritis. This may suggest that performing the OK procedure for more severe grade 3 arthritis could decrease reoperation rates. Further investigations are needed to better understand the indications for each surgical technique. This study is the largest cohort of open debridement and OK procedure with long term follow-up. We showed that open elbow debridement and the OK procedure have excellent survivorship until conversion to total elbow arthroplasty and are viable options in the treatment of primary elbow osteoarthritis and post traumatic cases. The OK procedure also has lower rates of revision surgery than open debridement, especially with more severe radiographic arthritis

Open debridement and Outerbridge and Kashiwagi debridement arthroplasty (OK procedure) are common surgical treatments for elbow arthritis. However, the literature contains little information on the long-term survivorship of these procedures. The purpose of this study was to determine the survivorship after elbow debridement techniques until conversion to total elbow arthroplasty and revision surgery. We performed a retrospective chart review of patients who underwent open elbow surgical debridement (open debridement, OK procedure) between 2000 and 2015. Patients were diagnosed with primary elbow osteoarthritis, post-traumatic arthritis, or inflammatory arthritis. A total of 320 patients had primary surgery including open debridement (n=142) and OK procedure (n=178), and of these 33 patients required a secondary revision surgery (open debridement, n=14 and OK procedure, n=19). The average follow-up time was 11.5 years (5.5 - 21.5 years). Survivorship was analyzed with Kaplan-Meier curves and Log Rank test. A Cox proportional hazards model was used assess the likelihood of conversion to total elbow arthroplasty or revision surgery while adjusting for covariates (age, gender, diagnosis). Significance was set p<0.05. Kaplan-Meier survival curves showed open debridement was 100.00% at 1 year, 99.25% at 5 years, and 98.49% at 10 years and for OK procedure 100.00% at 1 year, 98.80% at 5 years, 97.97% at 10 years (p=0.87) for conversion to total elbow arthroplasty. There was no difference in survivorship between procedures after adjusting for significant covariates with the cox proportional hazard model. The rate of revision for open debridement and OK procedure was similar at 11.31% rand 11.48% after 10 years respectively. There were higher rates of revision surgery in patients with open debridement (hazard ratio, 4.84 CI 1.29 - 18.17, p = 0.019) compared to OK procedure after adjusting for covariates. We also performed a stratified analysis with radiographic severity as an effect modifier and showed grade 3 arthritis did better with the OK procedure compared to open debridement for survivorship until revision surgery (p=0.05). However, this difference was not found for grade 1 or grade 2 arthritis. This may suggest that performing the OK procedure for more severe grade 3 arthritis could decrease reoperation rates. Further investigations are needed to better understand the indications for each surgical technique. This study is the largest cohort of open debridement and OK procedure with long term follow-up. We showed that open elbow debridement and the OK procedure have excellent survivorship until conversion to total elbow arthroplasty and are viable options in the treatment of primary elbow osteoarthritis and post traumatic cases. The OK procedure also has lower rates of revision surgery than open debridement, especially with more severe radiographic arthritis

We retrospectively assessed the value of identifying impinging osteophytes using dynamic computer simulation of CT scans of the elbow in assisting their arthroscopic removal in patients with osteoarthritis of the elbow. A total of 20 patients were treated (19 men and one woman, mean age 38 years (19 to 55)) and followed for a mean of 25 months (24 to 29). We located the impinging osteophytes dynamically using computerised three-dimensional models of the elbow based on CT data in three positions of flexion of the elbow. These were then removed arthroscopically and a capsular release was performed.

The mean loss of extension improved from 23° (10° to 45°) pre-operatively to 9° (0° to 25°) post-operatively, and the mean flexion improved from 121° (80° to 140°) pre-operatively to 130° (110° to 145°) post-operatively. The mean Mayo Elbow Performance Score improved from 62 (30 to 85) to 95 (70 to 100) post-operatively. All patients had pain in the elbow pre-operatively which disappeared or decreased post-operatively. According to their Mayo scores, 14 patients had an excellent clinical outcome and six a good outcome; 15 were very satisfied and five were satisfied with their post-operative outcome.

We recommend this technique in the surgical management of patients with osteoarthritis of the elbow.

Cite this article: Bone Joint J 2014;96-B:237–41.

Introduction. Wide, tumor-like resection for chronic osteomyelitis (COM), a standard practice previously, has been challenged recently with adequate, local debridement. This paper reviews the evolution of surgical debridement for long bone osteomyelitis, and presents the outcome of adequate debridement in a tertiary bone infection unit. Materials & Methods. Retrospective review of records from 2014 to 2020 of patients with long bone osteomyelitis. All records were searched electronically and imaging reviewed. All patients were managed by Multidisciplinary Infection Team protocol. Results. 53 patients (54 bones) with median age of 45.5 years (IQR 31 to 55) and mean follow-up of 29 months (12 – 59) were identified. According to Cierny-Mader classification, ten bones were type I, 39 were type III, and five were type IV; via the BACH classification of long bone osteomyelitis 21 were uncomplicated, 32 were complex, and one had limited options. All patients were treated with single-staged management with one planned second stage stabilization. Seventy-five percent grew positive microbial cultures. Forty-six (85%) cases had resolution of COM after index procedure and 51 (94%) had resolution at last follow up. Four (7%) patients underwent second surgical procedure and six (11%) patients had complications. Conclusions. We report high COM resolution rate through detailed pre operative evaluation and planning with multidisciplinary team approach. We challenge the need for wide tumor-like resection and the need for regenerative procedures in all cases of COM. Adequate debridement and local delivery of high concentration of antibiotic appears to provide comparable outcomes

In patients with hand sepsis does bedside debridement compared to operating theatre debridement have similar clinical outcomes, hospital cost and time to discharge in a District Hospital setting in South Africa?. A case series of 130 adult patients presenting to a district level orthopaedic unit over 1 year with hand sepsis requiring debridement. All included patients were debrided at the bedside (i.e. the emergency room, ward, OPD) under wrist or digital block. Patients excluded from the study included patients with necrotising soft tissue infections that required debridement in theatre. A cost analysis was done based on operating theatre (OT) costs saved as defined by Samuel1 et al. If an average theatre time of 45 min is taken then the cost saved per patient is approximately R1500 and approximately R300000 for the patients included in the case series. This excludes ward and other hospital costs related to a longer hospital admission. The mean time to discharge for the included patients was 24 hours. This study suggests that bedside debridement can be a viable and cost effective option for selected cases of hand sepsis that can avoid the high cost and time associated with operating theatre debridement with similar outcomes. This has implications for the future treatment of hand sepsis in resource constrained settings were operating theatre time is not only very expensive but also very scarce

Aims. The standard of wide tumour-like resection for chronic osteomyelitis (COM) has been challenged recently by adequate debridement. This paper reviews the evolution of surgical debridement for long bone COM, and presents the outcome of adequate debridement in a tertiary bone infection unit. Methods. We analyzed the retrospective record review from 2014 to 2020 of patients with long bone COM. All were managed by multidisciplinary infection team (MDT) protocol. Adequate debridement was employed for all cases, and no case of wide resection was included. Results. A total of 53 patients (54 bones) with median age of 45.5 years (interquartile range 31 to 55) and mean follow-up of 29 months (12 to 59) were included. In all, ten bones were Cierny-Mader type I, 39 were type III, and five were type IV. All patients were treated with single-staged management, except for one (planned two-stage stabilization). Positive microbial cultures grew in 75%. Overall, 46 cases (85%) had resolution of COM after index procedure, and 49 (90.7%) had resolution on last follow-up. Four patients (7%) underwent second surgical procedure and six patients (11%) had complications. Conclusion. We challenge the need for wide tumour-like resection in all cases of COM. Through detailed preoperative evaluation and planning with MDT approach, adequate debridement and local delivery of high concentration of antibiotic appears to provide comparable outcomes versus radical debridement. Cite this article: Bone Jt Open 2023;4(8):643–651

Aims. The study aimed to assess the clinical outcomes of arthroscopic debridement and partial excision in patients with traumatic central tears of the triangular fibrocartilage complex (TFCC), and to identify prognostic factors associated with unfavourable clinical outcomes. Methods. A retrospective analysis was conducted on patients arthroscopically diagnosed with Palmer 1 A lesions who underwent arthroscopic debridement and partial excision from March 2009 to February 2021, with a minimum follow-up of 24 months. Patients were assessed using the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, Mayo Wrist Score (MWS), and visual analogue scale (VAS) for pain. The poor outcome group was defined as patients whose preoperative and last follow-up clinical score difference was less than the minimal clinically important difference of the DASH score (10.83). Baseline characteristics, arthroscopic findings, and radiological factors (ulnar variance, MRI, or arthrography) were evaluated to predict poor clinical outcomes. Results. A total of 114 patients were enrolled in this study, with a mean follow-up period of 29.8 months (SD 14.4). The mean DASH score improved from 36.5 (SD 21.5) to 16.7 (SD 14.3), the mean MWS from 59.7 (SD 17.9) to 79.3 (SD 14.3), and the mean VAS pain score improved from 5.9 (SD 1.8) to 2.2 (SD 2.0) at the last follow-up (all p < 0.001). Among the 114 patients, 16 (14%) experienced poor clinical outcomes and ten (8.8%) required secondary ulnar shortening osteotomy. Positive ulnar variance was the only factor significantly associated with poor clinical outcomes (p < 0.001). Positive ulnar variance was present in 38 patients (33%); among them, eight patients (21%) required additional operations. Conclusion. Arthroscopic debridement alone appears to be an effective and safe initial treatment for patients with traumatic central TFCC tears. The presence of positive ulnar variance was associated with poor clinical outcomes, but close observation after arthroscopic debridement is more likely to be recommended than ulnar shortening osteotomy as a primary treatment. Cite this article: Bone Joint J 2024;106-B(4):380–386

Traditional mechanical debridement can only remove visibly infected tissue and is unable to completely clear all the biofilm that hides within muscle crevices and nerves. This study aims to determine the results of single-stage revision using noncontact low frequency ultrasonic debridement in treating chronic periprosthetic joint infections (PJI). A prospective study of consecutive patients requiring single-stage revision for chronic PJI was performed since August 2021. After mechanical debridement, an 8‑mm handheld non‑contact low‑frequency ultrasound probe was used for ultrasonic debridement at a frequency of (25±5) kHz and power of 90% for 5 minutes. Each ultrasound lasted 10 seconds with 3‑seconds intervals. The probe was repeatedly sonicated among all soft tissue and bsingle interface. The distal femoral canal and the posterior capsule of the knee were fully sonicated with a special right‑angle probe. Chemical debridement was then performed to irrigation the whole operative area. Recurrence of infection, culture results and number of colonies 24 hours after ultrasonic debridement were recorded. A total of 45 patients (25 hips and 20 knees) were included and 43 of them (95.6%) were free of infection at a mean follow-up time of 29 months (24 to 33). There were no intraoperative complications related to ultrasonic debridement (neurovascular and muscle injury, poor wound healing and fat liquefaction). The culture‑positive rate of wound liquid before ultrasonic debridement was 40.0% (18/45), which significantly increased to 75.6% (34/45) after ultrasonic debridement (P=0.001). The median number of colonies 24 hours after ultrasonic debridement was 2372 CFU/ml (310 to 4340 CFU/ml), which was significantly higher than that before debridement (307 CFU/ml; 10 to 980 CFU/ml) (P=0.000). Single-stage revision with non‑contact low‑frequency ultrasonic debridement can fully expose bacteria within biofilm, increase the efficacy of chemical debridement and lead to a favorable short‑term outcome without related complications

Aim. To describe the histopathology of the first and last debrided bone tissue in chronic osteomyelitis and answer the following research question; is the last debrided bone tissue viable and without signs of inflammation?. Method. In total, 15 patients with chronic osteomyelitis were allocated to surgical treatment using a one stage protocol including extensive debridement. Suspected infected bone tissue eradicated early in the debridement procedure was collected as a clearly infected sample (S1). Likewise, the last eradicated bone tissue was collected as a suspected non-infected sample (S2), representing the status of the bone void. In all cases, the surgeon debrided the bone until visual confirmation of healthy bleeding bone. The samples were processed for histology, i.e. decalcification and paraffin embedding, followed by cutting and staining with Haematoxylin and Eosin. Immunohistochemistry with MAC-387 antibodies towards the calprotectin of neutrophil granulocytes (NGs) was also performed and used for estimation of a neutrophil granulocyte (NG) score (0, 1, 2 or 3), by the method described for fracture related infections (1). Results. For the S1 samples the median NG score was 3 which is considered confirmatory for infection. However, following debridement the median NG score was significantly (p = 0.032) reduced to 2. Often NGs were seen as single cells, but in seven S1 samples and in one S2 sample massive NG accumulations were observed. The S1 samples showed a mix of granulation tissue, fibrosis, viable bone, and bone necrosis. The S2 samples contained viable bone tissue and occasionally (10/15) small fragments of necrotic bone or bone debris were seen. Furthermore, a large number of erythrocytes were observed in most S2 samples. Conclusions. The present study shows that the inflammatory response still existents after debridement, although the response fades from the center of infection. Therefore, sampling of debrided bone tissue for histology must be performed initially during surgery, to avoid underestimation of the inflammatory response, i.e. the NG score. The last debrided bone tissue cannot by definition be considered completely viable and caution should be made to remove blood (rinse) before intraoperative evaluation of the viability of debrided cancellous bone. Remnant necrotic bone fragments or debris could represent low-vascular hiding places for leftover bacteria. Application of local antibiotics might have a central role in clearing of these small non-viable bone pieces at the bone void interface

Introduction. Osteomyelitis is a challenge in diagnosis and treatment. 18F-FDG PET-CT provides a non-invasive tool for diagnosing and localizing osteomyelitis with a sensitivity reaching 94% and specificity reaching 100%. We aimed to assess the agreement in identifying the geographic area of infected bone and planned resection on plain X-ray versus 18F-FDG PET-CT. Materials & Methods. Clinical photos and X-rays of ten osteomyelitis patients were shown to ten consultant surgeons; they were asked to draw the area of infection and extent of planned surgical debridement; data will be compared to 18F-FDG PET-CT results. Results. We tested the agreement between the surgeons in every parameter. Regarding height, there was poor agreement between surgeons. Regarding perimeter, the ten surgeons showed low-moderate agreement. The ten surgeons showed a low-moderate agreement for circularity. Results document the variability of assessment and judgement based on plain X-rays. In comparison to PET-CT, All parameters were significantly different in favour of 18F-FDG PET-CT over X-ray (P < 0.001). Conclusions. 18F FDG PET-CT provides a three-dimensional tool for localizing the exact location of the infected bone and differentiating it from the normal bone. Thus, it could be beneficial in precise pre-operative planning and surgical debridement of chronic osteomyelitis

Aim. Debridement, Antibiotics, Irrigation, and implant Retention (DAIR) is a surgical treatment protocol suitable for some patients with fracture related infection (FRI). Clinically relevant pre-clinical models of DAIR are scarce and none have been developed in large animals. Therefore, this project aimed to develop a large animal model for FRI including a DAIR approach and compare outcomes after 2 or 5 weeks of infection. Method. Swiss Alpine sheep (n=8), (2–6 years, 50–80 kg) were included in this study. This study was approved by cantonal Ethical authorities in Chur, Switzerland. A 2 mm osteotomy was created in the tibia and fixed with a 10-hole 5.5 mm steel plate. Subsequently, 2.5 mL of saline solution containing 10. 6. CFU/mL of Staphylococcus aureus MSSA (ATCC 25923) was added over the plate. Sheep were observed for 2 (n=3) or 5 weeks (n=5) until revision surgery, during which visibly infected or necrotic tissues were removed, and the wound flushed with saline. All samples were collected for bacterial quantification. After revision surgery, the sheep were treated systemically for 2 weeks with flucloxacillin and for 4 weeks with rifampicin and cotrimoxazole. After 2 further weeks off antibiotics, the animals were euthanized. Bacteriological culture was performed at the end of the study. Bone cores were isolated from the osteotomy site and processed for Giemsa & Eosin and Brown and Brenn staining. A radiographical examination was performed every second week. Results. Bacteriological evaluation of the retrieved samples during revision surgery showed no significant difference between the 2 vs 5 weeks infection periods in term of total CFU counts. At the end of the study, radiographical examination showed callus formation over the osteotomy site in both groups, although the osteotomy was not completely healed in either group. At euthanasia, the 2 weeks infection group showed a higher soft tissue burden compared to the 5 weeks group, whereby the infection in the 5 weeks group was primarily located in the bone and bone marrow. Conclusions. The large animal model of FRI and DAIR was successfully established. Bacteriological outcomes highlight that the increasing duration of the infection does not change the outcome but the location of the infection from a predominantly soft tissue infection to a deeper bone and intramedullary (IM) channel infection. The debridement of the IM channel could potentially reduce the infection burden by eliminating those bacteria not easily reached by systemic antibiotics, though is not practical using conventional techniques

Abstract. Introduction. Periprosthetic joint infection (PJI) is a common cause of revision total knee surgery. Although debridement and implant retention (DAIR) has lower success rates in the chronic setting, it is an accepted treatment for acute PJI. There are two broad DAIR strategies: single debridement or a planned double debridement performed days apart. The purpose of this study is to evaluate the cost-effectiveness of single versus double DAIR with antibiotic beads for acute PJI in total knee arthroplasty (TKA). Methodology. A decision tree using single or double DAIR as treatment strategies for acute PJI was constructed. Quality Adjusted Life Years (QALYs) and costs associated with the two treatment arms were calculated. Treatment success rates, failure rates, and mortality rates were derived from the literature. Medical costs were derived from both the literature and Medicare data. A cost-effectiveness plane was constructed from multiple Monte Carlo trials. A sensitivity analysis identified parameters most influencing the optimal strategy decision. Results. Double DAIR with antibiotic beads was the optimal treatment strategy both in terms of the health utility state (82% of trials), and medical cost (97% of trials). Strategy tables demonstrated that as long as the success rate of double debridement is 10% or greater than the success rate of a single debridement, the two-stage protocol is cost-effective. Conclusions. This Markov analysis demonstrates that in the setting of acute PJI following TKA, a double DAIR with antibiotic beads is more cost effective than single DAIR from a societal perspective

Aim. To study the antimicrobial effect of a gentamicin loaded bio-composite bone void filler in relation to a limited or extensive debridement of osteomyelitis lesions, respectively. Methods. Nine pigs were inoculated into the right proximal tibial bone with a high virulent gentamicin sensitive strain of Staphylococcus aureus (10. 4. CFU). Seven days after inoculation, Group A pigs (n=3) were exposed to a limited debridement of the bone lesion, whereas Group B pigs (n=3) were exposed to an extensive debridement. The bone defects of Groups A and B were filled with (2–5 ml) of an absorbable gentamicin (175 mg/10 mL) loaded bio-composite. The animals of Group A and B were euthanized 12 days after revision surgery. Group C animals did not undergo revision surgery and were euthanized seven (n=1) or nineteen (n=2) days post inoculation in order to follow the development of the untreated infection. None of the animals were treated with systemic antimicrobials. All bones were exposed to a post mortem CT scan and rigours pathological examinations. The surrounding bone tissue and the bio-composite were sampled for microbiology. Results. All animals developed a substantial purulent bone infection in the inoculated leg prior to revision surgery. In the cases of limited debridement, the bone lesions surrounding the bio-composite bone void filler had clearly expanded since revision surgery, and contained extensive amounts of pus, necrotic bone tissue and oedematous fibrotic tissue. In the cases of extensive debridement, the bio-composite bone void filler was surrounded by only a few mm of fibrosis and sclerotic bone tissue i.e. the bone lesions were not expanding. However, in one pig the bio-composite bone void filler was communicating with a small purulent osteolytic lesion without a sclerotic border indicating appearance after revision surgery. In all pigs, S. aureus bacteria were post mortem cultured from the adjacent bone tissue and the bio-composite surface. Conclusions. The gentamicin concentrations within the bio-composite could not eradicate the residual infection after debridement. However, extensive debridement and filling of the bone void with gentamicin loaded bio-composite contained the lesion formed by revision surgery, which are important complementing roles as adjuvant to systemic antimicrobial therapy and the immune system in eradication of the infection. The present study emphasizes that extensive debridement is fundamental for successful treatment of bone infections and that antimicrobial loaded bone void fillers or bone substitutes should not be used as an alternative to extensive debridement

Aims. The principle strategies of fracture-related infection (FRI) treatment are debridement, antimicrobial therapy, and implant retention (DAIR) or debridement, antimicrobial therapy, and implant removal/exchange. Increasing the period between fracture fixation and FRI revision surgery is believed to be associated with higher failure rates after DAIR. However, a clear time-related cut-off has never been scientifically defined. This systematic review analyzed the influence of the interval between fracture fixation and FRI revision surgery on success rates after DAIR. Methods. A systematic literature search was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, in PubMed (including MEDLINE), Embase, and Web of Science Core Collection, investigating the outcome after DAIR procedures of long bone FRIs in clinical studies published until January 2020. Results. Six studies, comprising 276 patients, met the inclusion criteria. Data from this review showed that with a short duration of infection (up to three weeks) and under strict preconditions, retention of the implant is associated with high success rates of 86% to 100%. In delayed infections with a fracture fixation-FRI revision surgery interval of three to ten weeks, absence of recurrent infection was reported in 82% to 89%. Data on late FRIs, with a fracture fixation-FRI revision surgery interval of more than ten weeks, are scarce and a success rate of 67% was reported. Conclusion. Acute/early FRI, with a short duration of infection, can successfully be treated with DAIR up to ten weeks after osteosynthesis. The limited available data suggest that chronic/late onset FRI treated with DAIR may be associated with a higher rate of recurrence. Successful outcome is dependent on managing all aspects of the infection. Thus, time from fracture fixation is not the only factor that should be considered in treatment planning of FRI. Due to the heterogeneity of the available data, these conclusions have to be interpreted with caution. Cite this article: Bone Joint J 2021;103-B(2):213–221